Field of the Invention
The invention relates to a device for folding printing copies.
The published German Patent Document 40 18 707 A1 discloses a driving device for folding knives, which is used in polygraphic knife folding machines. Proceeding from an effort to obtain a wide-range adjustment of the height of a folding knife driven by a crank drive, the crank drive including the drive shaft thereof is vertically adjustably disposed. The changes in position of gears of a spur gear transmission associated therewith are assured by supporting rollers, by a connecting lever and by the influence of a pre-stressable compression spring. It is thereby possible to adjust the thus oscillating folding knife over a wide range without affecting the kinematics of the drive.
The published German Patent Document 29 17 616 C2 relates to a drive unit for a folding knife for folding planar items. This drive unit includes a linearly acting drive aggregate, which is represented by a traveling-field linear motor that is formed of a reaction part and a secondary part and that is movably mounted in a frame-fixed guide. The movable part of the traveling-field linear motor is arranged so as to be displaceable during the folding cycle, the linear motor being formed so as to be controllable by the sheet to be folded, and devices for dampening and counter-braking the movable part are provided in front of the return or reversal points of the movable part.
Due to the use of the linear motor in this improved arrangement, the resulting construction is not suitable for high speeds such as can occur in web-processing rotary printing presses, such as rotary newspaper web presses or jobbing or commercial rotary printing machines. With the improved embodiment according to the aforementioned published German Patent Document 29 17 616 C2, tilting of the folding knife cannot be completely prevented with respect to an off-center folding of sheets.
The published German Patent Document 30 46 051 A1 discloses a folding device for web-fed rotary printing presses. A folding device for web-fed rotary printing presses is proposed with which a longitudinal fold extending in the longitudinal direction of printing copies is formed in the printing copy. The longitudinal fold is formed in the printing copy after a cross-fold has been formed therein. A folding knife extending parallel to the transport direction of the printing copies is provided, and is suspended from two driving cranks rotating with the same rotary speed and being moved reciprocatingly. In a lower position thereof, the printing copies to be folded longitudinally are pushed between two driven folding rollers.
The suspension of the folding knife from the driving crank is effected via an additional crank. The latter is borne coaxially with pivot pins thereof at the crank pin of the driving crank. The additional crank is driven via a gear transmission at the same rotary speed as that of the driving crank, but in a direction opposite thereto, the crank pin of the additional crank executing a substantially or at least approximately vertical lifting motion.
This construction is precise because the gear transmission that is used is associated with a considerable production outlay, particularly with respect to gear teeth accuracy, which is to be produced in an involved and costly manner. This construction is therefore associated with high production costs.
Starting from the constructions of the prior art aforedescribed herein, it is an object of the invention to provide a device for folding printing copies which, moreover, generates a linearly extending lifting movement of the folding knife and which is associated with a minimal construction outlay.
With the foregoing and other objects in view, there is provided, in accordance with the invention, a device for folding printing copies in a web-fed rotary printing machine, comprising a folding knife, controls for reciprocatingly moving the folding knife at least approximately in one plane, the controls including a first and a second toggle lever, which, at one of the ends thereof, respectively, are movably attached to frame-fixed parts of the printing machine and at the other ends thereof, respectively, are movably attached to the folding knife, and a rotary element simultaneously actable upon both the first and the second toggle levers for operating the controls.
In accordance with a special feature of the invention, the folding knife serves for producing a second longitudinal fold in a printing copy in the transport direction of the respective printing copy.
In accordance with another feature of the invention, the rotary element is constructed as a double crank.
In accordance with a further feature of the invention, the toggle levers are connected to the double crank so that the toggle levers are driven at least approximately in parallel.
In accordance with an added feature of the invention, the rotary element is actable via a push rod upon the toggle levers, respectively.
In accordance with an additional feature of the invention, the rotary element is constructed as a single crank.
In accordance with yet another feature of the invention, the single crank is directly actable upon one of the toggle levers.
In accordance with yet a further feature of the invention, the second toggle lever is coupled via a push rod with the toggle lever upon which the single crank is directly actable.
In accordance with yet an added feature of the invention, the folding device includes vertical guides wherein the folding knife is guidable.
In accordance with yet an additional feature of the invention, the folding knife is movable at least approximately vertically up and down.
In accordance with still another feature of the invention, the toggle levers, respectively, are disposed by the one end thereof at a frame-fixed cross bar.
In accordance with still a further feature of the invention, the rotary element is cooperatively connected with the toggle levers so that when the rotary element rotates, the folding knife executes a reciprocatory motion.
In accordance with still an added feature of the invention, the rotary element is arranged centrally along an imaginary center line of the folding knife, and the two toggle levers are disposed on mutually opposite sides in vicinity of outer edges of the folding knife and are actable upon the folding knife.
In accordance with another aspect of the invention, there is provided a folder including a device for folding printing copies in a web-fed rotary printing machine, comprising a folding knife, controls for reciprocatingly moving the folding knife at least approximately in one plane, the controls including a first and a second toggle lever, which, at one of the ends thereof, respectively, are movably attached to frame-fixed parts of the printing machine and at the other ends thereof, respectively, are movably attached to the folding knife, and a rotary element simultaneously actable upon both the first and the second toggle levers for operating the controls.
In accordance with a concomitant aspect of the invention, there is provided an assembly including a folder having a longitudinal folding device for forming a second longitudinal fold in printing copies in a transport direction of the printing copies, the folder being preceded by a web-processing web-fed rotary printing machine, and the second longitudinal fold being producible after a cylinder crossfold is formed, the folding device comprising a folding knife accepted at two control members and being movable vertically up and down thereby, the folding knife, in a lower position thereof, serving to push printing copies between two driven folding rollers, the two control members being two driven toggle lever pairs disposed between a frame-fixed cross bar and the folding knife, and a rotary element for simultaneously controlling the toggle lever pairs, the rotary element being rotatable over one rotation thereof per one stroke of the folding knife.
The suspension of the folding knife, which is reciprocatingly movable in one plane, from driven toggle levers on frame-fixed parts of the printing machine enables an extremely high speed with great folding precision for a simple and cost-efficient structure by foregoing the use of gearing therein. Due to the drive introduction into the toggle levers, for example, at respective centrally disposed articulating points thereof, assurance is provided that identical motions extending in a horizontal plane are executed at both toggle levers, the motions being followed by a corresponding strictly linear reciprocatory motion of the folding knife. Because gearing or toothed wheel work is not used, the production costs for the folding device proposed in accordance with the invention can be reduced significantly; the linking points or articulating points of the components at the frame-fixed parts of the printing machine, at the rotary element producing the drive, as well as at the upper side of the folding knife, can be realized by bearing bushings, which are simple to produce and which have a long service life.
In an advantageous embodiment of the folding device according to the invention, the rotary element driving the toggle levers can be constructed as a double crank. The double-crank component makes it possible to link a number of driven elements at the circumference thereof and can be advantageously realized with respect to the linking points of the transmission elements at the circumference thereof with respect to the occurring knee forces. The two driven toggle levers can be driven in parallel by a double crank, so that identical vertical stroke paths result at both toggle levers. A stroke or lifting rod, which serves as a connecting rod at the same time and which can be manufactured quite simply, can be used advantageously as a power transmission element between the rotating double crank and the toggle levers which can be extended horizontally. By this construction, the rotation of the double-crank rotary element can be transformed into a vertical motion of the articulating point of a bipartite toggle lever.
In a further advantageous embodiment of the invention, the rotary element driving the toggle levers can be constructed as a single crank. The single crank can act directly upon one of the toggle levers to be driven. The second toggle lever, which is not directly driven, can be indirectly driven via a push rod proceeding from the directly driven toggle lever.
In an advantageous embodiment of the invention, the folding knife can be guided in vertical guides at both short side surfaces, so that no play can occur with respect to the folding knife guide, which would negatively influence the folding precision.
In an advantageous embodiment of the driven toggle levers, they have upper and lower parts, respectively, extending symmetrically from a linking point that can be outwardly extended in a horizontal plane, the upper parts being arranged in a frame-fixed cross bar of the folder, and the lower parts of the toggle levers being linked at the upper side of the folding knife that is reciprocable.
The folding device according to the invention for forming the second longitudinal fold in the transport direction of the printing copies can be utilized for folders for web-processing rotary printing machines which may be jobbing or commercial wed-fed rotary printing machines presses or newspaper web-fed rotary printing machines, and the folders can be realized as format-variable combination folders or as pinless folders.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a device for folding printing copies, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, wherein: